MOLECULAR PROPERTIES OF SUBTHRESHOLD POTASSIUM CHANNELS

描述：（改编自申请人摘要）长期 本提案的目的是了解分子机制 调节哺乳动物A型K+通道功能的基因。 这些K+ 通道激活，并迅速响应膜 去极化，它们的主要功能之一是控制 神经元重复放电时的峰间期。 因此，在本发明中， A型钾通道直接影响神经元信号编码， 是学习、记忆等复杂心理过程的基础。 认知功能。 两个不同的克隆A型K+通道将被 研究：由mKv4.1和人脑编码的小鼠脑通道 由hKv3.4编码的通道。 它们在膜电位下激活 负或正的神经元放电阈值， 调节这些K+功能的机制 渠道尚未探索。 重组DNA的组合 方法（例如，异源表达和体外诱变） 电生理学（电压钳和膜片钳记录）将 用于解决三个方面：第一，生物物理特性 mKv4.1编码的A型K+通道，在宏观和 单通道水平。 这些信息将作为 了解通道功能的调节。 第二，分子 调节小鼠和人类A型K+通道的机制 蛋白激酶C（PKC）。 在此要解决的具体问题是：i） PKC的激活如何控制特定K+通道的门控; ii） 所涉及的磷酸化位点的定位;和iii）所述磷酸化位点的 PKC作为不同A型K+通道调节剂意义 神经系统 第三，可调节门控的机制 A型K+通道（mKv4.1）在其天然环境中的作用。 具体探讨：i）单个K+通道如何通过 假定的本地因素;和ii）可能揭示 结构通道域参与。 研究分子 调节A型K+通道功能的机制可能 加强我们对神经系统受损的大脑功能的理解 和精神疾病

DESCRIPTION: (Adapted from applicant's abstract) The long-term objective of this proposal is to understand the molecular mechanisms that regulate the function of mammalian A-type K+ channels. These K+ channels activate and inactivate rapidly in response to membrane depolarization, and one of their main functions is to control the neuronal interspike interval in episodes of repetitive firing. Thus, A-type K+ channels directly influence neuronal signal coding that underlies such complex mental processes as learning, memory and other cognitive functions. Two distinct cloned A-type K+ channels will be investigated: mouse brain channels encoded by mKv4.1 and human brain channels encoded by hKv3.4. They activate at membrane potentials negative or positive to the neuronal firing threshold, respectively.The mechanisms that regulate the function of these K+ channels have not been explored. A combination of recombinant DNA methodology (e.g., heterologous expression and mutagenesis in vitro) and electrophysiology (voltage-clamp and patch-clamp recording) will be used to address three aspects: First, the biophysical properties of A-type K+ channels encoded by mKv4.1, at the macroscopic and single channel levels. This information will serve as the basis for understanding regulation of channel function. Second, the molecular mechanisms of regulation of mouse and human A-type K+ channels by protein kinase C (PKC). Specific questions to address here are: i) how activation of PKC controls gating of specific K+ channels; ii) mapping of the phosphorylation site(s) involved; and iii) the significance of PKC as regulator of distinct A-type K+ channels in the nervous system. Third, the mechanisms that may regulate gating of A-type K+ channels (mKv4.1) in their native environment. Specifically exploring: i) how single K+ channels are fine tuned by putative native factors; and ii) strategies that may reveal the structural channel domains involved. Studying the molecular mechanisms that regulate the function of A-type K+ channels may enhance our understanding of brain functions impaired in neurological and psychiatric disorders.